This video was taken from a NASA HU-25C Guardian chase plane looking toward NASA’s DC-8, with a Falcon 20-E5 from the German Aerospace Agency (DLR) soon to fly into the DC-8’s exhaust.
The Falcon is testing how it maneuvers in the contrail and the performance of onboard instruments it’ll use to sample exhaust and ice particles. The trip was one of several test-plan verification flights done on May 7, 2014, to prep for the next day’s start of the ACCESS II campaign to test emissions from the DC-8 using biofuel.